The present invention relates to a pneumatic device for retaining the chain of stitches at the commencement of stitching.
In the case of sewing machines which produce stitching on a series of pieces of fabric, for example, an overcasting operation, the machine is designed to continue this operation in the free space between a sewn piece of fabric and the succeeding piece of fabric and these pieces of fabric are adapted to be separated from one another by suitable cutting means as soon as they move beyond the presser foot of the sewing machine.
As a result, a section of the chain of stitches remains on the leading edge of the finished piece. This section must be turned back in the stitching formed in the piece itself so as not to spoil the appearance of the finished workpiece and to prevent the stitches from coming undone. It is already known in the art to fold back the afore-mentioned chain section within the stitching being produced on a piece of fabric but the devices for effecting this operation all have the disadvantage of considerably reducing visibility in the sewing zone; these known devices necessitate additional elements which are added to those normally provided in these zones on sewing machines to grip the free end of the chain projecting from the tongue of the needle plate so as to carry it in front of the needle in order to incorporate it in the new stitching being produced.